fixup! feat(observability): add OpenTelemetry logs

kong/observability/logs.lua

@@ -11,32 +11,42 @@ end
 
 local request_id_get = require "kong.observability.tracing.request_id".get
 local time_ns = require "kong.tools.time".time_ns
-local cycle_aware_deep_copy = require "kong.tools.utils".cycle_aware_deep_copy
+local deep_copy = require "kong.tools.utils".deep_copy
 
 local get_log_level = require "resty.kong.log".get_log_level
 local constants_log_levels = require "kong.constants".LOG_LEVELS
 
 local table_new = require "table.new"
-local table_clear = require "table.clear"
 local string_buffer = require "string.buffer"
 
 local ngx = ngx
 local kong = kong
 local table = table
 local tostring = tostring
 
+local ngx_null = ngx.null
+local table_pack = table.pack -- luacheck: ignore
+
 local MAX_WORKER_LOGS = 1000
 local MAX_REQUEST_LOGS = 1000
+local INITIAL_SIZE_WORKER_LOGS = 100
 local NGX_CTX_REQUEST_LOGS_KEY = "o11y_logs_request_scoped"
 
-local worker_logs = table_new(100, 0)
+local worker_logs = table_new(INITIAL_SIZE_WORKER_LOGS, 0)
 local logline_buf = string_buffer.new()
 
 
+-- WARNING: avoid using `ngx.log` in this function to prevent recursive loops
 local function configured_log_level()
   local ok, level = pcall(get_log_level)
   if not ok then
-    level = constants_log_levels[kong.configuration.log_level]
+    -- This is unexpected outside of the context of unit tests
+    local level_str = kong.configuration.log_level
+    _G.native_ngx_log(ngx.WARN,
+      "[observability] OpenTelemetry logs failed reading dynamic log level. " ..
+      "Using log level: " .. level_str .. " from configuration."
+    )
+    level = constants_log_levels[level_str]
   end
 
   return level
@@ -45,12 +55,21 @@ end
 
 -- needed because table.concat doesn't like booleans
 local function concat_tostring(tab)
-  if #tab == 0 then
+  local tab_len = #tab
+  if tab_len == 0 then
     return ""
   end
 
-  for i = 1, #tab do
-    logline_buf:put(tostring(tab[i]))
+  for i = 1, tab_len do
+    local value = tab[i]
+
+    if value == ngx_null then
+      value = "nil"
+    else
+      value = tostring(value)
+    end
+
+    logline_buf:put(value)
   end
 
   return logline_buf:get()
@@ -130,7 +149,7 @@ function _M.maybe_push(stack_level, log_level, ...)
   end
 
   -- no (or empty) log line
-  local args = { ... }
+  local args = table_pack(...)
   local log_str = concat_tostring(args)
   if log_str == "" then
     return
@@ -144,16 +163,15 @@ end
 
 
 function _M.get_worker_logs()
-  local wl = cycle_aware_deep_copy(worker_logs)
-
-  table_clear(worker_logs)
+  local wl = worker_logs
+  worker_logs = table_new(INITIAL_SIZE_WORKER_LOGS, 0)
   return wl
 end
 
 
 function _M.get_request_logs()
   local request_logs = get_request_log_buffer()
-  return cycle_aware_deep_copy(request_logs)
+  return deep_copy(request_logs)
 end
 
 

kong/plugins/opentelemetry/logs.lua

@@ -46,10 +46,12 @@ local function log(conf)
   local worker_logs = o11y_logs.get_worker_logs()
   local request_logs = o11y_logs.get_request_logs()
 
+  local worker_logs_len = #worker_logs
+  local request_logs_len = #request_logs
   ngx_log(ngx_DEBUG, _log_prefix, "total request_logs in current request: ",
-      #request_logs, " total worker_logs in current request: ", #worker_logs)
+      request_logs_len, " total worker_logs in current request: ", worker_logs_len)
 
-  if #request_logs + #worker_logs == 0 then
+  if request_logs_len + worker_logs_len == 0 then
     return
   end
 

kong/plugins/opentelemetry/otlp.lua

@@ -3,7 +3,7 @@ local pb = require "pb"
 local new_tab = require "table.new"
 local nkeys = require "table.nkeys"
 local tablepool = require "tablepool"
-local cycle_aware_deep_copy = require("kong.tools.table").cycle_aware_deep_copy
+local deep_copy = require("kong.tools.table").deep_copy
 
 local kong = kong
 local insert = table.insert
@@ -169,7 +169,7 @@ do
   encode_traces = function(spans, resource_attributes)
     local tab = tablepool_fetch(POOL_OTLP, 0, 2)
     if not tab.resource_spans then
-      tab.resource_spans = cycle_aware_deep_copy(pb_memo_trace.resource_spans)
+      tab.resource_spans = deep_copy(pb_memo_trace.resource_spans)
     end
 
     local resource = tab.resource_spans[1].resource
@@ -204,7 +204,7 @@ do
   encode_logs = function(log_batch, resource_attributes)
     local tab = tablepool_fetch(POOL_OTLP, 0, 3)
     if not tab.resource_logs then
-      tab.resource_logs = cycle_aware_deep_copy(pb_memo_log.resource_logs)
+      tab.resource_logs = deep_copy(pb_memo_log.resource_logs)
     end
 
     local resource = tab.resource_logs[1].resource

kong/plugins/opentelemetry/utils.lua

@@ -1,8 +1,8 @@
 local http = require "resty.http"
 local clone = require "table.clone"
-local null = ngx.null
 
 local tostring = tostring
+local null = ngx.null
 
 
 local CONTENT_TYPE_HEADER_NAME = "Content-Type"
@@ -52,4 +52,4 @@ return {
   http_export_request = http_export_request,
   get_headers = get_headers,
   _log_prefix = _log_prefix,
-}
+}